Improper access control in Zulip Server

1) Improper access control

EUVDB-ID: #VU87651

Risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2024-27286

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a remote user to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to an error in the moving messages feature when moving messages between stream or unsubscribing users from a stream. A remote user who previously had access to a stream can continue reading messages.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Zulip Server: 3.0 - 8.2

External links

http://github.com/zulip/zulip/security/advisories/GHSA-478x-rfqr-w4jf

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.